I bought a computer this tuesday, and up until now it worked fine. Last night, i left my computer on and went to bed. After waking up both my tower and monitor were in sleep, and both of them were not waking up. I was pressing every button, clicking and moving my mouse all over, but no luck. So i decided to restart my computer via the power button. The tower turned on, but the screen remained in sleep.
I turned my screen off and on, and the VGA and DVI signals flash to scanning, to No Signal and it went back to sleep. So i unplugged my DVI input (my tower and monitor has to use DVI) and plugged it back in. Still, no luck. I let it sit for a long period of time, and still, nothing. So i decided to get on my Father's computer to come report this to you guys. In that case...
Please do not provide me with downloads or links, because on my computer with a problem, i cannot access my computer, at all.
It's very likely the computer or video card is dead. Try a known good monitor with the system, if that works, it's not the computer, if both monitors don't work, PC is dead. In 95% of cases where people say there is a "monitor" issue with not getting a signal it's actually the COMPUTER issue with it not sending a signal to the monitor.
Is this a NEW computer, or a used one? If new, contact the tech support or the vendor. If used, check the motherboard for any issues, especially with capacitors to make sure those are all flat and not leaking anything or puffy. They should be flat and clean silver up top. Try reseating the power connections, video card, RAM. Try different RAM, try a new power supply, maybe a new video card (if it's not onboard).